U.S. Pat. No. 3,867,806 issued Feb. 25, 1975 and titled "Process of Making a Stretched-Wrapped Package" discloses an arrangement wherein a group of items to be enveloped by a stretchable film is mounted on a platform and rotated about a vertical axis so as to apply a stretchable film rotatable about a vertical axis to envelop the group of items. In this arrangement, the leading end of the stretch film is attached to the group of items to be packaged by hand and after the packaging operation is completed, the trailing end of the film strip is welded with a hot iron and severed using manual techniques. Tension of the stretch film is applied by a spring biased lever system. One objectionable feature of the arrangement of U.S. Pat. No. 3,867,806 resides in the fact that hand operations are required to secure the leading end of the film and to secure and sever the trailing end of the film as well as to cut off the trailing end of the film. Of course these manual operations constitute a significant item of cost in this type of operation.
U.S. Pat. No. 4,050,220 issued Sept. 27, 1977 and titled "Spiral Bundler" discloses an arrangement wherein a series of package groups are mounted end to end on guide rails and moved therealong while a stretch film is wound spirally about the groups of items. After the spiral is applied to a series of package groups, the spiral film is severed so as to separate each package group from the adjacent package group. The friction between the spirally wound stretchable film and the guides which support the moving packages constitute a significant impediment to the efficient and smooth operation of this packaging operation.
U.S. Pat. No. 4,050,221 issued Sept. 27, 1977 and titled "Stretch-Wrapped Package Process and Apparatus" discloses an arrangement similar to the above mentioned U.S. Pat. No. 3,867,806. In addition U.S. Pat. No. 4,050,221 discloses a brake device which is turned on and off during the packaging operation so as to control the tension of the wrap as the packaging operation progresses.
U.S. Pat. No. 4,077,179 issued Mar. 7, 1978 and titled "Automatic Wrapping Apparatus" discloses an arrangement in which items to be packaged are held in place by a clamp assembly and the stretchable film is wrapped about the group of items and the clamp assembly. Of course this apparatus and procedure are objectionable because of the difficulties encountered in removing the clamp assembly from the completed package.